Biomechanics of Training and Testing (eBook)

Jean-Benoit (JB) Morin is currently Full Professor at the Faculty of Sport Sciences of the University of Nice Sophia Antipolis (France). He is a member of the Laboratory of Human Motor Function, Education Sport and Health, and an associate researcher with the Auckland University of Technology Sports Performance Research Institute New Zealand (SPRINZ). He obtained a Track & Field Coach National Diploma in 1998 and graduated in Sport Science at the University of Besançon, France in 2000.He obtained his PhD in Human Locomotion and Performance in 2004 at the University of Saint-Etienne, France (supervised by Prof. Alain Belli), in collaboration with the University of Udine, Italy (Prof. Pietro diPrampero). He was an Assistant Professor at the Sport Science Department of the University of Saint-Etienne and member of the Laboratory of Exercise Physiology from 2005 to 2014.Pr Morin’s field of research is mainly human locomotion and performance, with specific interest into running biomechanics and maximal power movements (sprint, jumps). He teaches locomotion, sports biomechanics, and strength training and assessment methods. He has published over 100 peer-review Journal articles since 2002, and collaborates and plays a consultant role with elite sprinters, rugby and football teams (among other sports) all over the world.Pierre Samozino is an Associate Professor at the Sport Science department of University Savoie Mont Blanc in Chambery (France). His research activities, performed in the Inter-university Laboratory of Human Movement Biology (LIBM)  are mainly based on biomechanical approaches and focus on muscle mechanical properties in relation to sport performance and on human locomotion biomechanics. He obtained his PhD in Human Movement sciences in 2009 at the university of Saint-Etienne (France) supervised by Pr. Alain Belli, Dr. Frederique Hintzy and Dr. JB Morin. After two years as junior lecturer at the Sport Science Department of the University of Saint-Etienne from 2009 to 2010, he worked one year (2011) in the Biomechanics and Exercise Physiology Laboratory of the outdoor sport equipment company Salomon.The central part of his current research is to propose new concepts and simple methods to better understand the neuromuscular determinants of explosive performance (jumps, sprints, change of direction) and make possible their evaluation to the greatest number of sports practitioners, including strength and conditioning coaches in explosive sports (athletics, soccer, basketball, rugby ... ). Pierre Samozino teaches biomechanics, statistics and strength training for Bachelor and Master degree students. He is the author or co-author of over 60 peer review scientific papers from 2006, and collaborates with various sport teams and athletes.

Acknowledgements 5
Contents 6
1 Introduction 8
1.1 Optimizing Sport Performance Is like Cooking 9
1.2 See the Big Picture First 10
1.3 Simple Models, Simple Methods 10
References 11
Cycling 12
2 Maximal Force-Velocity and Power-Velocity Characteristics in Cycling: Assessment and Relevance 13
Abstract 13
2.1 Introduction 14
2.2 Measurement of Mechanical Output (Force, Velocity and Power) During Sprint Pedaling 15
2.3 Maximal Force- and Power-Velocity Relationships in Cycling 19
2.3.1 Testing and Processing 19
2.3.2 Meaning of the Indexes Extracted from the Relationships 21
2.4 Methodological Consideration and Practical Advices 25
2.4.1 Period of Averaging to Draw F-V or P-V Relationships and Duration of the Sprint 25
2.4.2 Quality of the F-V and P-V Models: “Calculated” Versus “True” Data 26
2.4.3 Main Factors to Control that may influence Maximal Power Output 27
2.5 Field Measurement in Ecological Condition 29
2.5.1 Mathematical Model of Sprint Cycling 30
2.5.2 Direct Measurement with Portable System 32
2.6 Conclusion 34
References 34
3 Mechanical Effectiveness and Coordination: New Insights into Sprint Cycling Performance 38
Abstract 38
3.1 Introduction 39
3.2 Torque Profile and Concept of Mechanical Effectiveness 40
3.2.1 Production of Power over the Pedaling Cycle 40
3.2.2 Mechanical Effectiveness: The Orientation of Pedal Force 44
3.3 Joint-Specific Power and Interest in Inverse Dynamics 47
3.3.1 Approach and Principle 47
3.3.2 Information Regarding Force and Power Capabilities in Cycling 48
3.4 Muscle Activity and Muscle Coordination 51
3.4.1 The Specificity of Muscle Coordination in Sprint Cycling 52
3.4.2 Coordination of Monoarticular and Biarticular Muscles 54
3.4.3 Muscle Coordination and Torque–Velocity Relationship 56
3.5 Practical Implications and Perspectives for Testing and Performance 58
3.5.1 Pedaling Effectiveness, Muscle Coordination and Performance: What’s the Link? 58
3.5.2 Outcomes Regarding the Meaning of Force–Velocity and Power–Velocity Relationships in Cycling and Perspectives for Testing and Training 62
3.6 Conclusion 64
References 65
Ballistic Movements of Upper and Lower Limbs 68
4 A Simple Method for Measuring Lower Limb Force, Velocity and Power Capabilities During Jumping 69
Abstract 69
4.1 Introduction 70
4.2 Force, Velocity, Power Mechanical Profile 72
4.2.1 Force-Velocity and Power-Velocity Relationships in Jumping 72
4.2.2 Force-Velocity Mechanical Profile in Jumping 74
4.3 Reference Testing Methods 77
4.3.1 Methodological Considerations 77
4.3.2 Laboratory Methods 79
4.3.3 Field Methods 82
4.3.4 Limitations of the Reference Methods 84
4.4 A Simple Method for Measuring Force, Velocity and Power During Jumping 85
4.4.1 Theoretical Bases and Equations 85
4.4.2 Limits of the Method 86
4.4.3 Validation of the Method 87
4.5 Technologies and Input Measurements 89
4.5.1 Jump Height 89
4.5.2 Push-off Distance 90
4.6 Practical Applications 91
4.7 Conclusion 94
References 95
5 Optimal Force-Velocity Profile in Ballistic Push-off: Measurement and Relationship with Performance 101
Abstract 101
5.1 Introduction 102
5.2 Force, Velocity, Power Capabilities & Performance
5.2.1 Performance and Maximal Power Output 103
5.2.2 Performance and Force-velocity Mechanical Profile 104
5.2.3 Biomechanical Models Applied to Ballistic Push-off 105
5.3 An Optimal Force-Velocity Mechanical Profile During Jumping 106
5.3.1 Theoretical Bases and Equations of the Biomechanical Model 106
5.3.2 Validation of the Model 108
5.3.3 Muscular Capabilities Determining Jumping Performance 109
5.3.4 FV Imbalance & Performance
5.4 Practical Applications 114
5.4.1 F-v Profile & F-v Imbalance Indices
5.4.2 FV Imbalance & Case Reports
5.4.3 FV Profile and Training 117
5.4.4 FV Imbalance, “Optimized” Training & Performance
5.5 Conclusion 119
References 121
6 A Simple Method for Measuring Lower Limb Stiffness in Hopping 124
Abstract 124
6.1 Introduction 124
6.2 Lower Limb Stiffness in Hopping 126
6.2.1 The Mechanical Definition of Stiffness 126
6.2.2 Spring-Like Leg Behaviour in Human Hopping 126
6.2.3 Modulation of Leg Stiffness in Hopping 128
6.2.4 Mechanisms for Regulating Leg Stiffness in Hopping 130
6.2.5 Measurement of Leg Stiffness in Hopping: The Reference Methods 131
6.2.6 Limitations of the Reference Methods 133
6.3 A Simple Method for Measuring Leg Stiffness in Hopping 134
6.3.1 Theoretical Foundations of the Method 134
6.3.2 Experimental Validation of the Method 135
6.3.3 Advantages and Limitations of the Method 136
6.3.4 Application of the Method 137
6.4 Conclusion 138
References 139
7 A Simple Method for Measuring Force, Velocity, Power and Force-Velocity Profile of Upper Limbs 142
Abstract 142
7.1 Introduction 143
7.2 The Force, Velocity, Power Mechanical Profile 144
7.2.1 Importance of the Upper Limb Inertia During the Bench Press 144
7.2.2 Consequence of the Upper Limb Inertia on the Force-Velocity Profile 147
7.3 A Simple Model of the Bench Press Exercise 149
7.3.1 Importance of the Shoulder During the Bench Press 149
7.3.2 A Simple Model Based on Three Segments: Shoulder, Arm and Forearm 150
7.3.3 Kinematic Parameters 153
7.3.4 Kinetic Parameters—Validation of the Model 155
7.4 A Simple Method for Measuring Force, Velocity and Power During the Bench Press Exercise 156
7.4.1 Theoretical Bases and Equations 156
7.4.2 Validation of the Method 158
7.4.3 Limits of the Method 159
7.4.4 Practical Applications 160
7.5 Conclusion 162
References 163
Running 166
8 A Simple Method for Measuring Lower Limb Stiffness During Running 167
Abstract 167
8.1 Introduction 168
8.2 The Spring-Mass Model of Running 169
8.2.1 Spring Stiffness 170
8.2.2 Spring-Mass Behavior During Bouncing and Running 170
8.2.3 Spring-Mass Stiffness in Running: Definitions and Assumptions 171
8.2.4 Reference Methods and Typical Values 173
8.2.5 Limitations of the Reference Methods 177
8.3 A Simple Method for Measuring Stiffness During Running 178
8.3.1 Theoretical Bases and Equations 178
8.3.2 Validation of the Method 179
8.3.3 Input Variables and Importance of Contact Time 179
8.3.4 Limits of the Method 181
8.4 Technologies and Input Measurements 182
8.5 Applications 188
8.5.1 Sprint Running 189
8.5.2 Ultra-endurance 191
References 192
9 A Simple Method for Determining Foot Strike Pattern During Running 196
Abstract 196
9.1 Introduction: Why Evaluate Foot Strike Pattern? 196
9.1.1 Foot Strike Pattern and Running-Related Injuries 197
9.1.2 Foot Strike Pattern and Performance 198
9.2 Existing Methods to Evaluate Foot Strike Pattern: Definitions and Limits 199
9.2.1 Measurement of Foot Strike Angle by 2D Motion Analysis 199
9.2.2 Measurement of Foot Strike Index from Kinetics 199
9.3 A Novel Field Method Based on Acceleration Measurements 200
9.3.1 Material and Data Analysis 200
9.3.2 Reliability 202
9.4 Field Applications 203
References 209
10 The Measurement of Sprint Mechanics Using Instrumented Treadmills 212
Abstract 212
10.1 Introduction 213
10.2 Devices 214
10.2.1 Early Non-motorized Treadmills 215
10.2.2 Modern Non-motorized Treadmills 216
10.2.3 Motorized Treadmills 217
10.2.4 Motorized Treadmills Equipped with Force Sensors 217
10.3 Sprint Acceleration Mechanics on a Motorized Instrumented Treadmill 219
10.3.1 Kinematics and Kinetics 222
10.3.2 Force-Velocity and Power-Velocity Relationships 222
10.3.3 Effectiveness of Ground Force Application 224
10.4 Limitations and Future Studies 231
10.4.1 Main Limitations 231
10.4.2 Latest Studies and Future Research 233
References 234
11 A Simple Method for Measuring Force, Velocity and Power Capabilities and Mechanical Effectiveness During Sprint Running 238
Abstract 238
11.1 Introduction 239
11.2 Theoretical Bases and Equations 241
11.3 Limits of the Method 245
11.4 Validation of the Method 247
11.4.1 Concurrent Validity Compared to Force Plate Measurements 247
11.4.2 Reliability 249
11.5 Technologies and Input Measurements 250
11.5.1 Split Times 250
11.5.2 Instantaneous Velocity 252
11.6 Practical Applications 256
11.6.1 Testing Considerations 256
11.6.2 Data Interpretation 257
11.6.3 Optimization of Sprint Acceleration Performance 258
11.6.4 Hamstring Injury Prevention and Monitoring of the Return to Sport 261
11.6.5 Better Understanding of the Limit of Human Sprinting Performance 263
11.7 Conclusion 265
References 266
12 The Energy Cost of Sprint Running and the Energy Balance of Current World Records from 100 to 5000 m 269
Abstract 269
12.1 Introduction 270
12.2 The Energy Cost of Sprint Running 271
12.3 Theory 272
12.4 Methods 275
12.5 Metabolic Power and Overall Energy Expenditure 277
12.6 Aerobic Versus Anaerobic Energy Expenditure 281
12.7 Discussion 286
12.8 Critique of Methods 288
12.9 Conclusions and Practical Remarks 290
Acknowledgements 291
Appendix 292
References 295
13 Metabolic Power and Oxygen Consumption in Soccer: Facts and Theories 298
Abstract 298
13.1 Introduction 299
13.2 Theory 299
13.3 Metabolic Power and Oxygen Consumption 302
13.4 The Role of the Energy Cost in Setting Metabolic Power Estimates 306
13.5 The Limits of Metabolic Power Assessment 311
13.6 Conclusions 312
Acknowledgements 312
References 312